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Study On The Phenomena Of Electrical Characteristic And Field Effect Transistor With 2-(4-hydroxyphenyl)-5-pyrimidinol

Posted on:2007-04-19Degree:MasterType:Thesis
Country:ChinaCandidate:H F ZhangFull Text:PDF
GTID:2178360212999200Subject:Condensed matter physics
Abstract/Summary:PDF Full Text Request
Recent progress in organic electroluminescence display technology has led to a new stage of the research of organic semiconductor. Organic field effect transistor (OFET) is an active device to control the conductibility of solid state material with the change of electrical field, and can be used for active matrix drive circuit in electron paper and flexible flat panel display. However, some problems such as higher operating voltage, lower field effect mobility and on/off ratio, have hindered its further development. So it is very necessary to advance various performances by obtaining the novel materials, shortening the channel length, and achieving highly ordered structure and arrangement in organic thin film.In this thesis, we fabricated and researched organic field effect transistor (OFET) with organic polarizable material 2-(4-hydroxyphenyl)-5-pyrimidinol, including liquid OFET, bulk crystal OFET and thin film crystal OFET. The qualitative operating modes in these devices used for explaining the performance were proposed in detail.During the fabrication and research of liquid OFET, the phenomenon of current vibration was presented with the applied gate voltage when the current flowed through organic polarizable material 2-(4-hydroxyphenyl)-5-pyrimidinol dissolved in N,N-Dimethylformamide (DMF) solution. We observed the change of periodical time in current vibration with the different gate voltage, the different voltage between source electrode and drain electrode, the different channel length, and the different resistance parallel-connected with the device. According to these performances, we presented a qualitative liquid polarizable molecule mode used for explaining current vibration.We fabricated and studied thin-film-crystal OFET with organic polarizable thin film of 2-(4-hydroxyphenyl)-5-pyrimidinol. The patterning technique of shallow evaporation was used for the fabrication of electron channel as long as 20μm and as wide as 10mm. After accomplishing the measurement for the device, we found three types of device performance with the different morphology. Also, we observed the anomalous electrical properties of the devices, including the normal IDS-VDS curves of OFETs, the battery properties of the devices controlled by the applied VG, and the disappearance of the field effect performance when the sample was measured many times.In addition, we fabricated and studied polycrystal OFET with the same organic polarizable material as the above device. To avoid the influence of the ambient atmosphere on the device performance, the crystal process of organic polarizable thin film, the fabrication of metallic electrodes and the measurement for the device were accomplished in the vacuum thermal evaporation system. The electron channel with the length of less than 100nm and the width of 0.1mm was fabricated by electromigration. The deposition at high substrate temperature and in situ postdeposition annealing with the help of in situ treatment of acetone for organic thin film were used for forming crystalline thin film. The device exhibited the similar performance with the above thin-film-crystal OFET. Based on these device performances, we proposed a qualitative organic polarizable crystalline grain mode to explain the above phenomenon.
Keywords/Search Tags:liquid OFET, crystalline OFET, current vibration, organic polarizable thin film, anomalous current, battery effect
PDF Full Text Request
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